Methods for producing a dielectric, dielectric having self-generating pores, monomer for porous dielectrics, process for preparing poly-o-hydroxyamides, process for preparing ploybenzoxazoles, and processes for producing an electronic component

ABSTRACT

Poly-o-hydroxyamides include binaphthyl substituents as repeating units. The poly-o-hydroxyamides can be cyclized to give the polybenzoxazole by heating. Pore formation occurs, so that a dielectric having a very low dielectric constant k of less than 2.5 is obtained.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional application of application Ser. No. 10/424,376,filed Apr. 28, 2003; the application also claims the priority, under 35U.S.C. §119, of German patent application DE 102 18 788.6, filed Apr.26, 2002; the prior applications are herewith incorporated by referencein their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to poly-o-hydroxyamides, a process for theirpreparation, polybenzoxazoles, and a process for their preparation,monomers for the preparation of the poly-o-hydroxyamides, an electroniccomponent that contains the polybenzoxazoles as a dielectric, and aprocess for the production of such electronic components.

In order to avoid cross-talk of signals which is caused by capacitivecoupling, adjacent conductor tracks in microchips are insulated from oneanother by a dielectric disposed between the conductor tracks. Compoundsthat are to be used as a dielectric must meet various requirements.Thus, the signal transit time in microchips depends both on the materialof the conductor track and on the dielectric that is disposed betweenthe conductor tracks. The lower the dielectric constant of thedielectric, the shorter too is the signal transit time. The dielectricsused to date are based on silica and have a dielectric constant of aboutfour (4). These materials are gradually being replaced by organicdielectrics that have a substantially lower dielectric constant. Thedielectric constant of these materials is generally below three (3).

In the microchips customary at present, the conductor tracks preferablyare formed from aluminum, AlCu, or AlCuSi. With increasing integrationdensity of the memory chips, there is a changeover to copper asconductor track material, owing to its lower electrical resistance incomparison with aluminum. Copper permits shorter signal transit time andhence a reduction in the conductor track cross section. In contrast tothe techniques customary to date, in which the dielectric is introducedinto the trenches between the conductor tracks, in the copper damascenetechnique, the dielectric is first structured. The resulting trenchesare first coated with a very thin barrier that is composed, for example,of titanium, titanium nitride, tantalum, tantalum nitride, siliconcarbide, silicon nitride, or silicon carbonitride. The trenches are thenfirst filled with copper and then excess copper is ground offmechanically. The dielectric must therefore be stable to the materialsused for the grinding and must have sufficient adhesion to the substratein order to avoid becoming detached during the mechanical grindingprocess. Furthermore, the dielectrics must also have sufficientstability in the following process steps in which further components ofthe microchips are produced. For this purpose, they must, for example,have sufficient thermal stability and must not undergo decompositioneven at temperatures of more than 400° C. Moreover, the dielectric mustbe stable to process chemicals, such as solvents, strippers, bases,acids or aggressive gases. Further requirements are good solubility anda sufficient shelf-life of the intermediates from which the dielectricsare produced.

With unfluorinated polymers that have sufficient thermal stability,dielectric constants down to about 2.5 are obtainable. By fluorinationof the polymers, it is true that the dielectric constant can be furtherreduced. However, these materials have poor adhesion to the substrateand, at high temperatures, eliminate fluorine-containing decompositionproducts, which may damage the chip.

In order to be able to provide materials having a dielectric constant of<2.5, porous materials are currently being investigated in more detail.Owing to the air-filled nanopores, the dielectric constant decreases tovalues of two (2) or less. However, the porosity of the materials mustnot be chosen too high because their mechanical stability otherwisegreatly decreases and the dielectric does not withstand mechanical loadsas occur in chemical mechanical planarization (CMP). Furthermore, theprocessing of the currently available porous dielectric is verydifficult because both the process conditions and the solvent used havea great influence on pore size and pore size distribution. In mostcases, the production of pores is effected by thermal decompositionreactions that have to be very exactly controlled. The decompositionproducts enter the air or ovens and, in addition to soiling and damagingthe apparatuses, can also constitute a health hazard.

U.S. Pat. No. 5,776,990 to Hedrick, et al. describes a porous polymerhaving a mean pore size of less than 100 nm. The copolymer is formedfrom thermally stable and thermally labile blocks. If a film of such apolymer is heated above the decomposition temperature of the labileblock, a porous dielectric forms. In order to obtain the desired poresize, however, exact control of the process conditions is required, suchas the sequence of temperature steps or the solvent used. Furthermore,gaseous byproducts that can soil or damage the apparatuses used and thatare hazardous to health form.

Polybenzoxazoles (PBO) are polymers that have very high heat stability.The substances are already used for the production of protective andinsulating layers. Polybenzoxazoles can be prepared by cyclization ofpoly-o-hydroxyamides. The poly-o-hydroxyamides have good solubility inorganic solvents and good film formation properties. They can easily beapplied to electronic components by using the spin coating technique.After a thermal treatment in which the poly-o-hydroxyamide is cyclicizedto give the polybenzoxazole, a polymer that has the desired propertiesis obtained. Polybenzoxazoles can also be processed directly in theircyclized form. In this case, however, there are as a rule difficultieswith the solubility of the polymer. Building blocks ofpoly-o-hydroxyamides are described, for example, in commonly-ownedGerman Patent Application DE 100 11 608, which corresponds to U.S. Pat.No. 6,531,632 B2.

The mechanism taking place in the cyclization of poly-o-hydroxyamides topolybenzoxazoles is shown schematically below:

Upon heating, the o-hydroxyamide undergoes cyclization to give theoxazole; water is liberated.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide methods forproducing a dielectric, a dielectric having self-generating pores, amonomer for porous dielectrics, a process for preparingpoly-o-hydroxyamides, a process for preparing polybenzoxazoles, aprocesses for producing an electronic component, and a method forforming a dielectric that overcome the hereinafore-mentioneddisadvantages of the heretofore-known devices of this general type andthat provide and involve polymers that can be easily applied toelectronic components and that have a good electrical insulating effectafter their cyclization and exhibit sufficient thermal stability andvery good adhesive and filling properties.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a poly-o-hydroxyamide having a Formula I:

in which

E¹ and E², in each case independently, are hydrogen, a hydroxyl group ora saturated or unsaturated monovalent hydrocarbon substituents that mayalso contain one or more hetero atoms;

Y¹ and Y², in each case independently for each position, are a divalenthydrocarbon substituent which may also contain one or more hetero atoms;

Z¹, in each case independently for each position, is a structural unitof the Formula IIa or IIb

in which the bond (-*) and the substituent -GR⁵ are configured in theortho position relative to one another,

Z², in each case independently for each position, is a tetravalenthydrocarbon substituent which is composed of alkyl and/or arylsubstituents linked to one another and may also include one or morehetero atoms;

R¹, R², R³, and R⁴, in each case independently, are H, —C₆H₅,—(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃, —CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂,-G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)3, —(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is H, —CO(CH₂)_(n)—CH₃,—COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃, —CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂,—C(CH₃)₃, —(CF₂)_(n)—CF₃, —CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃,—(CH₂)_(n)-C₆H₅, —COO—(CH₂)_(n)—C₆H₅,

G is oxygen or sulfur,

a is 0 or 1,

b has a value of from 1 to 200,

c has a value of from 0 to 200,

d is 0 or 1, and

n is an integer from 0 to 10.

For reasons of simplicity, both the poly-o-hydroxyamides (G=0) and thepoly-o-thioamides (G=S) of the Formula I are referred to below aspoly-o-hydroxyamides. Statements made in connection with the polymergroups described above apply in context to both classes of compounds.Formula I represents a polymer having a continuous polymer backbone. Forreasons of simplicity, however, the molecule in Formula I wasrepresented in two parts.

The poly-o-hydroxyamides of the Formula I, according to the invention,form, on cyclization to give the polybenzoxazole, pores having amagnitude of a few ten nanometers without it being necessary to providea component, for example a thermally labile block or an additive, in thepolymer material. The pore size is influenced primarily by the structureof the poly-o-hydroxyamide of the Formula I and only to a small extentby the process conditions, i.e. the solvent used and the temperatureprogram. It is not necessary to provide additional components that aredecomposed to give gaseous products, in order to produce pores.Consequently, during pore formation, no impurities form and no damage isdone to the microchip structures already produced. After thecyclization, the polybenzoxazoles obtained have dielectric constants ofless than 2.5, owing to the porosity of the material, which correspondsto the lower limit of the fluorine-free polybenzoxazoles having highthermal stability. The adhesion of the polybenzoxazole prepared from thepoly-o-hydroxyamide of the Formula I to surfaces relevant for chiptechnology, such as silicon, silicon carbide, silicon carbonitride,silicon nitride, silica, titanium, tantalum, titanium nitride, tantalumnitride or silicon oxynitride, is very good. Furthermore, thepolybenzoxazoles have high stability to chemicals as used in theproduction of microchips, such as solvents, strippers, bases, acids, oraggressive gases. The polymer materials are therefore very suitable formicroelectronic applications. Moreover, the materials are alsooutstandingly suitable for the copper damascene technique. During thecopper grinding process, no disadvantageous effects occur, such asdelamination, cracking or blister formation. The poly-o-hydroxyamides ofthe Formula I, according to the invention, are very readily soluble inmany organic solvents. Solvents that may be used are, for example,acetone, cyclohexanone, diethylene glycol monoethyl or diethyl ether,N-methylpyrrolidone, y-butyrolactone, ethyl lactate, methoxypropylacetate, tetrahydrofuran, ethyl acetate and mixtures of said solvents.The solutions can be very readily applied to surfaces of electroniccomponents e.g. by spin coating, spraying or dip methods and have a verygood film quality. Trenches having a width of less than 100 nm and anaspect ratio of >4 can also be filled without difficulties. Thepoly-o-hydroxyamides according to the invention can be cyclized byheating to temperatures of 200 to 500° C. Apart from the desired poreformation, there is no formation of defects, such as cracks in thefilled trenches.

The poly-o-hydroxyamides of the Formula I are prepared frombis-o-aminophenols and dicarboxylic acids or their derivatives. Thesubstituents derived from the dicarboxylic acids can have a wide varietyof structures. They may include saturated, unsaturated or aromatichydrocarbon substituents, combinations of these substituents also beingpossible. Saturated substituents may be straight-chain or branched.Furthermore, one or more carbon atoms may also be replaced byheteroatoms, or the substituents Y¹ and Y² may also have groups formedfrom a plurality of heteroatoms. Heteroatoms are understood here asmeaning atoms which are not carbon or hydrogen. Particularly preferredheteroatoms are O, N, S, Si, and P. The chain length determined by theindices a, b, c, and d can be controlled by the reaction conditions, forexample by using the rate of addition of the starting materials or bycontrolling the temperature at which the reaction is performed. Ofcourse, a distribution of chain lengths is obtained in such apolymerization, the reaction being carried out in such a way that theaverage chain length is within the range of values indicated above forthe indices a, b, c, and d. A narrow molecular weight distribution ofthe polymers is desirable. For the index b, the reaction is controlledin such a way that values in the range of 1 to 200, preferably 4 to 80,result. For the index c, the reaction is performed in such a way thatvalues in the range of 0 to 200, preferably 0 to 50, result. Themolecular weights or averaged chain lengths can be determined bycustomary methods, e.g. gel permeation chromatography (GPC).

The properties of the polymer are substantially determined by the groupZ¹. In the group Z¹, the substituents R¹, R², R³, and R⁴ areparticularly preferably hydrogen atoms and the substituents GR⁵ areparticularly preferably a hydroxyl group or acetyl group. These groupsZ¹ permit cyclization to give the benzoxazole under comparatively mildconditions. Particularly preferred structures for the group Z¹ (formulaeIIa and IIb) are shown below:

In addition to the groups Z¹, the polymer may also include furthergroups Z² which do not include any binaphthyl substituents. The groupsZ² may have a very varied range of structures. The groups Z² preferablyinclude 6 to 30 carbon atoms. The group Z² preferably includes one ortwo phenyl groups on which the group GR⁵ and the nitrogen atomcontinuing the polymer chain are bonded. The group GR⁵ and the nitrogenatom are preferably disposed in the ortho position relative to oneanother in order also to permit cyclization to give the oxazole in thecase the groups Z². The part-structures of the group Z², in particularphenyl groups, which carry the groups GR⁵ can be linked via alkyleneand/or arylene groups or via groups formed from hetero atoms. The groupsZ² can be substituted by monovalent groups, in particular alkyl groups.In particular, Z² is a structural unit which is selected from the group:

in which R⁶ is a divalent substituent that is selected from thefollowing group:

in which

R⁷ is an alkyl substituent having 1 to 10 carbon atoms or an arylsubstituent having 5 to 22 carbon atoms; and

e is an integer from 1 to 10.

G in groups Z¹ and Z² is preferably an oxygen atom.

Among the abovementioned substituents R⁵, the following substituents areparticularly preferred:

in which m is an integer from 0 to 10, in particular from 0 to 5.

The groups Y¹ and Y² may likewise have a very large variety ofstructures and preferably include 5 to 30 carbon atoms. The groups Y¹and Y² may include saturated and unsaturated hydrocarbon groups aspart-structures, aromatic hydrocarbon groups being preferred.

Examples of suitable divalent substituents of the groups Y¹ and Y² areshown below.

in which:

f is an integer from 1 to 10; and

g is an integer from 1 to 10.

Poly-o-hydroxyamide of the Formula I may carry, as terminal groups E¹and E², a hydrogen atom or a hydroxyl group or a saturated orunsaturated monovalent hydrocarbon substituent which may also containone or more hetero atoms. The hydrocarbon substituent preferablyincludes 1 to 30 carbon atoms. Some examples of suitable terminal groupsE¹ and E² are shown below.

If, in formula I, a=0 and/or d=0, i.e. if E¹ and/or E² are bonded to NH,E¹ and E², in each case independently of one another, are preferablyselected from the following group:

If, in Formula I, a=1 and/or d=1, i.e. the substituents E¹ and E² arebonded to CO, E¹ and E², in each case independently of one another, arepreferably selected from the following group:

in which R⁸ is selected from the following group:

in which

h is 0-10, and

q is *—O—*, *—S—*, or *—NH—*.

The terminal groups E¹ and E² can be introduced into thepoly-o-hydroxyamides of the Formula I by corresponding activeprecursors, for example acid chlorides.

The structures shown for the substituents Y¹, Y², E¹, and E² representonly a selection of preferred structures. However, this list should notbe considered as being definitive.

As already mentioned, the polybenzoxazoles obtained from thepoly-o-hydroxyamides of the Formula I by cyclization have advantageousproperties with respect to the thermal stability, the mechanicalstrength and the electrical insulating effect. The invention thereforealso relates to polybenzoxazoles of the Formula III

in which

and a, b, c, d, R¹, R², R³, R⁴, R⁵, Y¹, Y², E¹, E², and G have themeaning stated in the case of Formula I.

For reasons of simplicity, both polybenzoxazoles (G=0) andpolybenzothiazoles (G=S) of the Formula III are referred to aspolybenzoxazoles. The structures of the groups shown in the Formula IIIare equally applicable to both classes of compounds. Formula IIIrepresents a polymer having a continuous polymer backbone. For reasonsof simplicity, however, the molecule in Formula III has been shown intwo parts.

The poly-o-hydroxyamides of Formula I can be prepared by reactingbis-o-aminophenols or bis-o-aminothiophenols with dicarboxylic acids ortheir activated derivatives. The invention therefore also relates tomonomers of the Formulae IVa and IVb:

in which R¹, R², R³, R⁴, R⁵, and G have the meanings stated in the caseof Formula I.

The monomers of the Formulae IVa and IVb are prepared by customarysynthesis processes, as described, for example, in Organikum, Wiley-VCH,1999, page 228 et seq., page 324 et seq. and page 340 et seq. Similarmonomers are described, for example, in U.S. Pat. No 4,525,539 or inEuropean Patent No. EP 0 317 942.

The monomers of the Formulae IVa and IVb can be reacted withdicarboxylic acids or their activated derivatives to give the desiredpoly-o-hydroxyamides of the Formula I. The invention therefore alsorelates to a process for the preparation of poly-o-hydroxyamides of theFormula I, monomers of the Formula IVa and/or IVb being reacted with adicarboxylic acid or an activated dicarboxylic acid derivative of theFormulae Va and/or Vb.

in which L is a hydroxyl group or an activating group and Y¹ and Y² havethe meaning stated in the case of Formula I. For example, acid chloridesor activated esters, for example sulfonic acid esters, can be used as anactivating group for the dicarboxylic acid derivatives of the formula V.The reaction of the monomers of the Formula IVa or IVb and of thedicarboxylic acids of the Formulae Va and Vb can, however, also beeffected in the presence of a compound that activates the carboxylicacid, such as, for example, carbonyldiimidazole ordicyclohexylcarbodiimide. In principle, all reagents which bind thewater formed in the reaction to themselves are suitable. For thepreparation of the poly-o-hydroxyamides of the Formula I, the monomersof the Formula IVa or IVb and the dicarboxylic acid(s) or optionally thedicarboxylic acid derivatives of the Formula Va or Vb are reacted in anorganic solvent at −20 to 150° C. in the course of 5 to 20 hours. Ifrequired, terminal groups of the polymer can be blocked with a suitablereagent in order thus to introduce the terminal groups E¹ and E².Suitable-reagents have already been described in the explanation of thecompounds of the Formula I. The poly-o-hydroxyamide of the formula Iwhich has formed after the reaction is precipitated by dropwise additionof the reaction solution to a precipitating agent, washed and dried.Suitable precipitating agents are water and alcohols, such asisopropanol, butanol, or ethanol. Mixtures of these precipitating agentsmay also be used. It is also suitable for the precipitating agent tocontain from 0.1% to 10% of ammonia. After filtration and drying, theprecipitated polymer can be directly further processed and, for examplefor application to a semiconductor substrate, can be dissolved in one ofthe solvents mentioned further above.

The polymerization to give the poly-o-hydroxyamide of the Formula I canbe carried out in the presence of a base in order to trap acidliberated. Suitable basic acid acceptors are, for example, pyridine,triethylamine, diazabicyclooctane, or polyvinylpyridine. However, otherbasic acid acceptors may also be used. Compounds that are readilysoluble in the solvent used for the synthesis, for exampleN-methylpyrrolidone, and in the precipitating agent, for example wateror water/alcohol mixtures, are those that are completely insoluble inthe solvent, such as, for example, crosslinked polyvinylpyridine, areparticularly preferred. The acid acceptors can then easily be separatedfrom the resulting poly-o-hydroxyamide during the working up of thereaction product.

Particularly suitable solvents for the polymer synthesis areγ-butyrolactone, tetrahydrofuran, N-methylpyrrolidone, anddimethylacetamide. However, any solvent in which the starting componentsare readily soluble can in principle be used.

The invention furthermore relates to a process for the preparation ofpolybenzoxazoles of the Formula III, poly-o-hydroxyamides of the FormulaI being heated. Heating results in the formation of an oxazole ring orthiazole ring with elimination of a small molecule, in general water,the polybenzoxazoles of the Formula III, according to the invention,being obtained. The pore formation that occurs is influenced only to aslight extent by the reaction conditions. The pores have a diameter inthe region of a few ten nanometers and a narrow pore distribution. Theprocess therefore permits large tolerances in the production of thedielectric, which substantially simplifies the reaction procedure.

The polybenzoxazole of Formula III, which is prepared by the processaccording to the invention, has a very low dielectric constant of k≦2.5,owing to the pores enclosed in the dielectric. It adheres very well tosurfaces relevant to chip technology, such as silicon, silicon carbide,silicon carbonitride, silicon nitride, silica, titanium, tantalum,titanium nitride, tantalum nitride, or silicon oxynitride. The inventiontherefore also relates to an electronic component that contains thepolybenzoxazole of Formula III described above. Polybenzoxazole ofFormula III may be disposed, for example, as a dielectric betweenconductor tracks or conductor track planes or as a buffer layer betweenthe microchip and the housing surrounding it. The dielectrics accordingto the invention are outstandingly suitable for the copper damascenetechnique. During the grinding process, no disadvantageous effects, suchas delamination, cracking or blister formation, occur.

The invention therefore also relates to a process for the production ofan electronic component, a solution of a poly-o-hydroxyamide of theFormula I in a solvent first being prepared. This solution is applied toa substrate and the solvent is evaporated so that a film is obtained.The film is then heated in order to cyclize the poly-o-hydroxyamide andconvert it into the polybenzoxazole of Formula III. The film is thenstructured in order to obtain a resist structure which has trenches. Aconductive material, for example copper, is then deposited on the resiststructure so that the trenches are filled with a conductive material.Finally, excess conductive material is removed.

For example, lithographic processes can be used for structuring thepolybenzoxazole film, an etch-resistant mask being produced on the film.The structure of the mask is then transferred into the film of thepolybenzoxazole according to the invention by etching. Copper ispreferably used as conductive material. A barrier can be providedbetween dielectric and conductive material. For example, the materialsalready mentioned further above are suitable as material for thebarrier. Excess conductive material is removed, for example, by chemicalmechanical planarization.

The invention furthermore relates to a process for the production of anelectronic component, a solution of a poly-o-hydroxyamide of Formula Idescribed above first being prepared in a solvent. The solution is thenapplied to a substrate that already has on its surface metallicstructures between which trenches are formed. Such structures are, forexample, conductor tracks. The solvent is evaporated so that thetrenches are filled with the poly-o-hydroxyamide. Finally, the substrateis heated in order to cyclize the poly-o-hydroxyamide to give apolybenzoxazole.

The adhesion of the polyhydroxyamides to surfaces relevant inmicroelectronics, such as, for example, silicon, silica, siliconnitride, tantalum nitride, glass or quartz, can be improved by addingadhesion promoters.

For example, the following compounds can be used as adhesion promoters:

Other features that are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin methods for producing a dielectric, a dielectric havingself-generating pores, a monomer for porous dielectrics, a process forpreparing poly-o-hydroxyamides, a process for preparingpolybenzoxazoles, a processes for producing an electronic component, anda method for forming a dielectric, it is nevertheless not intended to belimited to the details shown, since various modifications and structuralchanges may be made therein without departing from the spirit of theinvention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial diagrammatic and partial schematic drawing showing asetup according to the invention for determining an dielectric constant;and

FIG. 2 is a photograph showing a shadow mask as used in example 25 forthe production of electrodes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLE 1 Bis-o-aminophenolshaving Oxygen Bridges:

Stage 1

The corresponding bishydroxybinaphthyl and3-fluoro-6-nitrobenzyloxyphenol are initially introduced under inert gas(nitrogen or argon) into a three-necked flask that is provided with astirrer and an inert gas connection, and N,N-dimethylformamide is addedto these at room temperature. The mixture is stirred for about 10 to 20minutes at room temperature. Thereafter, potassium carbonate is added inportions to the solution under inert gas. The solution is stirred at anelevated temperature for a few hours. The reaction temperature issuitably chosen from 60 to 140° C. The reaction occurs over course of 1to 10 hours. In addition to N,N-dimethylformamide, for example,N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, ordimethylacetamide can also be used. The concentrations of the startingmaterials are suitably chosen in a range from 5 to 50% by weight.

The suspension formed is cooled to room temperature and poured into acooled (2-10° C.), aqueous potassium hydroxide solution. The product isprecipitated in crystalline form. The precipitation can be acceleratedby adding ethyl acetate. The product is filtered, washed with water, andthen added to a 10% strength solution of acetic acid in water. Thesolution is stirred for 15 to 30 minutes, filtered, washed with waterand dried under inert gas at 40° C./100 mbar in a drying oven until theweight remains constant. The crude product obtained in this manner isrecrystallized from a solution in tetrahydrofuran and petroleum etherand dried again under reduced pressure.

Stage 2 (Hydrogenation and Simultaneous Elimination of the BenzylProtective Group):

The hydrogenation is effected by known hydrogenation processes for nitrocompounds, as described, for example, in European Patent No. EP 905 121,example 8. For this purpose, the nitro compound obtained in stage 1 canbe dissolved, for example, in tetrahydrofuran, palladium on activecarbon added and hydrogenation effected with hydrogen atsuperatmospheric pressure in an autoclave.

The bis((3-benzyloxy-4-nitro)phenoxy)binaphthyl prepared in stage 1 isdissolved in tetrahdyrofuran, and palladium on active carbon is addedunder inert gas. The amount of Pd/C is about 10% of the amount of thecompound to be hydrogenated. The suspension is introduced into apreviously heated hydrogenation reactor under argon inert gas andhydrogenated with hydrogen at room temperature under pressure. Thehydrogenation time is in general 10 to 50 hours. The hydrogen pressureis suitably chosen from 0.5 to 5 bar. The concentration of the compoundto be hydrogenated in tetrahydrofuran is 5 to 30% by weight. Instead oftetrahydrofuran, for example, dioxane, halogenated hydrocarbons ortoluene can also be used as the solvent.

After the hydrogenation, the suspension is transferred under inert gasinto pure ethanol, and concentrated hydrochloric acid is added withstirring until a clear solution forms. After the product has completelydissolved, the solution is filtered over a Bütchner funnel in order toremove the Pd catalyst. Thereafter, about 70% of the amount of solventis distilled off under reduced pressure and the concentrated solution isadded to a solution of diethyl ether and acetone (volume ratio 7:3) withrapid stirring. During this procedure, the product is precipitated incrystalline form. The suspension is stored for 12-24 hours at 0° C. to18° C. The product is then filtered off with suction and dried. Theaminophenol is present as the hydrochloride. In contrast to the freeaminophenol the form is not so greatly sensitive to oxidation byatmospheric oxygen.

EXAMPLE 2 Bis-o-aminophenols Without Oxygen Bridges

Stage 1

Moistened silica is initially introduced into a three-necked flaskprovided with a stirrer, a reflux condenser and an inert gas connection,and 10% strength sulfuric acid is added. The ratios are chosen at about10 parts by weight of silica per 6 parts by weight of 10% strengthsulfuric acid. 200 parts by weight of dichloromethane and 10 parts byweight of dihydroxybinaphthyl are then added in this sequence. About 10parts by weight of 65% strength nitric acid are then added at atemperature of 2 to 10° C. in the course of 15 to 60 minutes. After theend of the addition, the suspension is stirred until quantitativeconversion of the starting material at room temperature. Theabovementioned ratio can be changed in a range of up to about 20%.Instead of dichloromethane, other halogenated hydrocarbons may also beused as the solvent.

After complete conversion, the suspension is filtered. The product,which is present adsorbed onto the SiO₂ surface, is dissolved in asuitable solvent, such as, for example, acetone or ethyl acetate, andfiltered. This procedure is repeated twice. The organic fractions arecombined and evaporated down. The concentrated solution is slowly pouredinto dimethyl ether while stirring, and the precipitated product isfiltered off with suction. The product is then dried under inert gas at40° C./100 mbar in a drying oven until the weight remains constant.

Stage 2:

The hydrogenation of the compound obtained in stage 1 is carried out inthe same manner as described in example 1.

EXAMPLE 3 Synthesis of 2,2′-diacetoxy-3,3′-diamino-1,1′-binaphthyl asthe hydrochloride

Stage 1: 2,2′-Diacetoxy-3,3′-dinitro-1,1′-binaphthyl

4.088 g (14.29 mmol) of 2,2′-dihydroxy-1,1′-binaphthyl in 50 ml ofacetic anhydride are initially introduced into a 250 ml three-neckedflask provided with a reflux condenser, a KPG stirrer and an inert gasconnection and are dissolved. A solution of 4.35 ml (42.80 mmol) ofnitric acid (62%) in 25 ml of acetic anhydride is then added dropwise tothe solution at 0° C. in the course of 30 min. At the same temperature,stirring is carried out for 4 h and the precipitated orange-red solid isfiltered off with suction on a frit. After the end of the reaction, themixture is carefully poured in 500 ml of ice water and thoroughlystirred. The solid nitro product is filtered off with suction andthoroughly washed with water.

The crude product is dissolved in toluene at room temperature (2 ml/g)and heated to 90° C. and petroleum ether (4 ml/g) is added untilcrystallization begins. Thereafter, the suspension is slowly cooled toroom temperature, and the suspension is stored for a further 4 h in afreezer at −18° C. and then filtered. The product obtained is dried for24 h at 200 mbar and 55° C.

Yield 5.72 g (87% of theory)

Stage 2: 2,2′-Diacetoxy-3,3′-diamino-1,1′-binaphthyl hydrochloride

The hydrogenation is effected according to known processes for thehydrogenation of nitro compounds, as described, for example, in EuropeanPatent No. EP 905 121, example 8.

31.09 g (67.57 mmol) of 2,2′-diacetoxy-3,3′-dinitro-1,1′-binaphthyl aredissolved in 600 ml of tetrahydrofuran, and 5.00 g of 5% Pd/C are addedunder inert gas. The suspension is introduced under Ar inert gas into apreviously heated hydrogenation reactor and hydrogenated at roomtemperature for 24 h and under 2 bar H₂ pressure.

The suspension is then transferred under inert gas into 200 ml ofethanol. 10 ml of concentrated HCl are added with stirring and, when theproduct has completely dissolved, filtration is effected three timesover a Büchner funnel to remove the Pd catalyst. The solution thusobtained is evaporated down to about 20 ml of ethanol at 70° C. and 300mbar and then added to a solution of 700 ml of diethyl ether and 30 mlof acetone with rapid stirring. The suspension is stored for 24 h at−18° C. and the solid is filtered off and dried.

Yield: 28.65 g (90% of theory)

Preparation of the polymers

Chemicals used

Bisaminophenols:

2,21-Di(4-amino-3-hydroxyphenyloxy)-1,1l′-binaphthyl—(bisaminophenol 1)

3,3′-Diamino-2,2′-dihydroxy-1,1′-binaphthyl—(bis-amino-phenol 2)

9,9′-Bis(3-amino-4-hydroxyphenyl)fluorene—(bisamino-phenol 3)

4,4′-Diamino-3,3′-dihydroxybiphenyl—(bisaminophenol 4)

2,2′-Diacetoxy-3,3′-diamino-1,1′-binaphthyl—(bis-amino-phenol 5)

Dicarboxylic acid chlorides

Naphthalene-2,6-dicarboxylic acid chloride—(dicarboxylic acid chloride1)

Biphenyl-4,4′-dicarboxylic acid chloride (dicarboxylic acid chloride 2)

phenyl-4,4′-dicarboxylic acid chloride—(dicarboxylic acid chloride 3)

Terephthaloyl chloride (dicarboxylic acid chloride 4)

5-Phenylethynylisophthoyl chloride—(dicarboxylic acid chloride 5)

5-Allyloxyisophthaloyl dichloride—(dicarboxylic acid chloride 6)

Endcaps (E¹, E²):

Methacryloyl chloride—(Endcap 1)

5-Norbornene-2-carboxylic acid chloride—(Endcap 2)

5-Norbornene-2,3-dicarboxylic acid anhydride (Endcap 3)

EXAMPLE 4 Synthesis of polymer 1

50 g (0.1 mmol) of bisaminophenol 1 are dissolved in 400 ml of distilledN-methylpyrrolidone (NMP). A solution of 23.93 g (0.095 mol) ofdicarboxylic acid chloride 1, dissolved in 200 ml of distilled NMP isadded dropwise to this solution at 10° C. while stirring. Stirring iscontinued for a further hour at 10° C. and then for one hour at 20° C.After further cooling to 10° C., 1.64 g (0.01 mol) of endcap 3,dissolved in 50 ml of distilled y-butyrolactone (γ-BL) are addeddropwise to the reaction mixture, and stirring is carried out for onehour at 10° C. and then for one hour at 20° C. The reaction solution iscooled to 10° C., after which 19.76 g (0.25 mol) of pyridine, dissolvedin 30 ml of distilled γ-BL, are added to said reaction solution and thelatter is warmed up to room temperature and stirred for 2 hours.

In order to isolate the polymer, the reaction mixture is filtered andthe filtrate is added dropwise to a mixture of 1 1 of demineralizedwater and 200 ml of isopropanol while stirring, a further 3 l ofdemineralized water being added during the dropwise addition. Theprecipitated polymer is filtered off with suction and washed with 2 l ofcold demineralized water. After the filtration with suction, the polymeris stirred twice for 1 hour at room temperature in 2.5 portions of a 3%strength ammonia solution and then filtered off with suction. Thepolymer is washed neutral with demineralized water, filtered off, anddried for 72 hours at 50° C./10 mbar.

The polymer prepared in this manner is readily soluble in solvents suchas NMP, γ-BL, cyclohexanone, cyclopentanone or mixtures thereof.

EXAMPLE 5 Synthesis of polymer 2

15.81 g (0.05 mol) of bisaminophenol 2 are dissolved in 200 ml ofdistilled NMP. A solution of 8.82 g (0.03 mol) of dicarboxylic acidchloride 3 and 3.53 g (0.0175 mol) of dicarboxylic acid chloride 4 in150 ml of distilled γ-BL is added dropwise to this solution at 10° C.while stirring. Stirring is continued for a further hour at 10° C. andthen for 1 hour at 20° C. After further cooling to 10° C., 0.52 g (0.005mol) of endcap 1, dissolved in 20 ml of distilled γ-BL, is addeddropwise to the reaction mixture, and stirring is carried out for 1 hourat 10° C. and then for 1 hour at 20° C. The reaction mixture is cooledto 10° C., after which 9.48 g (0.12 mol) of pyridine, dissolved in 30 mlof distilled γ-BL, are added to said reaction mixture and the latter iswarmed up to room temperature and stirred for 2 hour.

Polymer 2 is isolated and worked-up analogously to example 4.

EXAMPLE 6 Synthesis of polymer 3

25 g (0.05 mol) of bisaminophenol 1 are dissolved in 200 ml of distilledNMP. A solution of 5.56 g (0.02 mol) of dicarboxylic acid chloride 2 in80 ml of distilled γ-BL is added dropwise to this solution at 10° C.while stirring. Stirring is carried out for a further hour at 10° C. andthen for 1 hour at 20° C. Cooling is effected at 10° C. and 5.55 g(0.0275 mol) of dicarboxylic acid chloride 4, dissolved in 80 ml ofdistilled γ-BL, are added dropwise. Stirring is carried out for afurther hour at 10° C. and then for 1 hour at 20° C. After cooling to10° C., 0.78 g (0.005 mol) of endcap 2 dissolved in 20 ml of distilledγ-BL is added dropwise to the reaction mixture, and stirring is carriedout for 1 hour at 10° C. and then for 1 hour at 20° C. The reactionmixture is cooled to 10° C., after which 11.85 g (0.15 mol) of pyridine,dissolved in 50 ml of distilled γ-BL, are added and said reactionmixture is warmed up to room temperature and stirred for 2 hours.

Polymer 3 is isolated and worked-up analogously to example 4.

EXAMPLE 7 Synthesis of polymer 4

25 g (0.05 mol) of bisaminophenol 1 and 20 g (0.05 mol) ofbisaminophenol 5 are dissolved in 400 ml of distilled NMP. A solution of27.93 g (0.095 mol) of dicarboxylic acid chloride 3 in 150 ml ofdistilled γ-BL is added dropwise to this solution at 10° C. whilestirring. Stirring is continued for a further hour at 10° C. and thenfor 1 hour at 20° C. After further cooling to 10° C., 1.64 g (0.01 mol)of endcap 3, dissolved in 20 ml of distilled γ-BL, are added dropwise tothe reaction mixture and stirring is carried out for 1 hour at 10° C.and then for 1 hour at 20° C. The reaction mixture is cooled to 10° C.,after which 19.76 g (0.25 mol) of pyridine, dissolved in 50 ml ofdistilled γ-BL, are added and said reaction mixture is warmed up to roomtemperature and stirred for 2 hours.

Polymer 4 is isolated and worked-up analogously to example 4.

EXAMPLE 8 Synthesis of polymer 5

18.97 g (0.06 mol) of bisaminophenol 2 and 15.2 g (0.04 mol) ofbisaminophenol 3 are dissolved in 300 ml of distilled NMP. A solution of14.7 g (0.05 mol) of dicarboxylic acid chloride 3 and 13.59 g (0.045mol) of dicarboxylic acid chloride 5, dissolved in 250 ml of distilledγ-BL, are added dropwise to this solution at 10° C. while stirring.Stirring is continued for 1 hour at 10° C. and for 1 hour at 200C. Afterfurther cooling to 10° C., 1.56 g (0.01 mol) of endcap 2, dissolved in50 ml of distilled γ-BL, are added dropwise to the reaction mixture, andstirring is carried out for 1 hour at 10° C. and then for 1 hour at 20°C. The reaction mixture is cooled to 10° C., after which 19.76 g (0.25mol) of pyridine, dissolved in 50 ml of distilled γ-BL, are added andsaid reaction mixture is warmed up to room temperature and stirred for 2hours.

The isolation and working-up of polymer 5 are effected analogously toexample 4.

EXAMPLE 9 Synthesis of polymer 6

30.01 g (0.06 mol) of bisaminophenol 1 are dissolved in 220 ml ofdistilled NMP. A solution of 11.11 g (0.055 mol) of dicarboxylic acidchloride 1 in 80 ml of distilled γ-BL are added dropwise to thissolution at 10° C. while stirring. Stirring is continued for 1 hour at10° C. and for 1 hour at 20° C. Cooling is effected to 10° C. and 15.2 g(0.04 mol) of bisaminophenol 3, dissolved in 80 ml of distilled γ-BL,are added dropwise. Stirring is continued for 1 hour at 10° C. and thenfor 1 hour at 20° C. Further cooling is effected to 10° C. and 12.08 g(0.04 mol) of dicarboxylic acid chloride 5, dissolved in 80 ml ofdistilled 7-BL, are added dropwise. Stirring is carried out for afurther hour at 10° C. and then for 1 hour at 20° C. After furthercooling to 10° C., 1.04 g (0.01 mol) of endcap 1, dissolved in 20 ml ofdistilled γ-BL, are added dropwise to the reaction mixture, and stirringis carried out for 1 hour at 10° C. and then for 1 hour at 20° C. Thereaction mixture is cooled to 10° C., after which 19.76 g (0.25 mol) ofpyridine, dissolved in 50 ml of distilled γ-BL, were added and saidreaction mixture is warmed up to room temperature and stirred for 2hours.

Polymer 6 is isolated and worked-up analogously to example 4.

EXAMPLE 10 Determination of Thermal Stabilities

All polymers described have thermal stabilities of >480° C. according toTGA investigations (apparatus: STA 1500 from Rheometric Scientific,heating rate: 5 K/min, inert gas: argon). The isothermal mass loss perhour (at 425° C.) is <0.7%. The polymers described therefore meet therequirements for use as insulation in microchips.

EXAMPLE 11 Preparation of Polymer Solutions

25 g of the polymers described in examples 4 to 9 are dissolved in 75 gof distilled NMP or distilled γ-BL. The dissolution process isexpediently effected on a shaking apparatus at room temperature. Thesolution is then filtered under pressure through a 0.2 μm filter into acleaned, particle-free glass sample tube. The viscosity of the polymersolution can be changed by varying the dissolved mass of polymer.

EXAMPLE 12 Improvement of the Adhesion by Adhesion Promoter Solutions

0.5 g of adhesion promoter (e.g.N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane) are dissolved in 95g of methanol, ethanol or isopropanol and 5 g of demineralized water atroom temperature in a cleaned, particle-free sample tube. After standingfor 24 h at room temperature, the adhesion promoter solution is readyfor use. This solution is usable for 3 weeks at the most.

The adhesion promoter should give a monomolecular layer on the surfaceof the parts to be adhesively bonded. The adhesion promoter canexpediently be applied by the spin coating technique. For this purpose,the adhesion promoter solution is applied via a 0.2 μm prefilter to thesurface to be adhesively bonded and is spun for 30 s at 5 000 rpm. Adrying step is then effected for 60 s at 100° C.

EXAMPLE 13 Application of a Polymer by the Spin Coating Method andCyclization to Give the polybenzoxazole

A processed silicon wafer that has lands and trenches up to a minimumdimension of, in each case, about 150 nm is coated, as described inexample 10, with an adhesion promoter. The filtered solution of polymer1, which was obtained according to example 11, is then applied to thewafer by using a syringe and is uniformly distributed using a spincoater. The spin coater speed is 2,000 rpm. The polymer is then heatedon a hotplate for 1 min at 120° C. and for 2 min at 200° C. The coatedwafer is then heated under nitrogen or argon in an oven to 425° C. for60 min. The polybenzoxazole thus obtained is inert to acids, bases andorganic solvents.

EXAMPLE 14 Determination of the Adhesion of the Polymers to a TitaniumNitride Layer

A 4″ silicon wafer is sputtered with a 50 nm thick titanium nitridelayer. The solution prepared in example 11 is applied to this wafer byspin coating, at 500 rpm for 5 s and at 2,000 rpm for 25 s. After ashort softbake of 1 min at 120° C. on a hotplate, 10 silicon chipshaving an edge length of 4×4 mm2, which had likewise been sputtered witha 50 nm thick titanium nitride layer, are then pressed onto the polymerfilm with a force of 2 N. This stack is then heated in a nitrogenatmosphere for 1 h at 425° C. in an oven. Following cooling to roomtemperature, an adhesion test was carried out using a shear tester, Dageseries 400. The mean value for polymer 1 that was required for shearingoff the chips is 15.51 N/mm².

EXAMPLE 15 Determination of the Adhesion of the Polymers to a TantalumNitride Layer

The experiment carried out was the same as that described in Example 14,but the surface of the wafer and of the chips was formed not of titaniumnitride but of tantalum nitride. The mean value of the force for polymer1 that was required for shearing off the chips is 16.01 N/mm².

EXAMPLE 16 Determination of the Adhesion of the Polymer to a SiliconSurface

The experiment carried out is the same as that described in Example 14,but the surface of the wafer and of the chips is formed not of titaniumnitride but of silicon. The mean value of the force for polymer 1 thatwas required for shearing off the chips is 17.05 N/mm².

EXAMPLE 17 Determination of the Adhesion of the Polymers to a SiliconNitride Layer

The experiment carried out is the same as that described in Example 14,but the surface of the wafer and of the chips is not formed of titaniumnitride but of silicon nitride. The mean value of the force for polymer1 that was required for shearing off the chips is 15.16 N/mm².

EXAMPLE 18 Determination of the Adhesion of the Polymers to a SilicaLayer

The experiment carried out is the same as that described in example 14,but the surface of the wafer and of the chips is formed not of titaniumnitride but of silica. The mean value of the force for polymer 1 thatwas required for shearing off the chips is 16.20 N/mm².

EXAMPLE 19 Determination of the Adhesion of the Polymers to a SiliconCarbide Layer

The experiment carried out is the same as that described in Example 14,but the surface of the wafer and of the chips was not formed of titaniumnitride but of silicon carbide. The mean value of the force for polymer1 that was required for shearing off the chips is 15.73 N/mm².

EXAMPLE 20 Determination of the Adhesion of the Polymers to a TantalumLayer

The experiment carried out is the same as that described in Example 14,but the surface of the wafer and of the chips was not formed of titaniumnitride but of tantalum. The mean value of the force for polymer 1 thatwas required for shearing off the chips is 16.68 N/mm².

EXAMPLE 21 Determination of the Adhesion of the Polymers to a TitaniumLayer

The experiment carried out is the same as that described in example 14,but the surface of the wafer and of the chips were formed not oftitanium nitride but of titanium. The mean value of the force forpolymer 1 that was required for shearing off the chips is 15.84 N/mm².

EXAMPLE 22 Determination of the Adhesion of the Polymers to a PolyimideLayer

The experiment carried out is the same as that described in Example 14,but the surface of the wafer and of the chips was not formed of titaniumnitride but of polyimide. The mean value of the force for polymer 1 thatwas required for shearing off the chips is 16.26 N/mm².

EXAMPLE 23 Comparative Example for Adhesion

A polymer was prepared analogously to Example 1 of U.S. Pat. No.5,077,378 and a polymer solution in NMP was prepared as described inExample 11. The adhesion of the polymer was then determined as describedin examples 14 to 22. The following mean values were found: TABLE 1Adhesion of the comparative polymers Surface Force for shearing off(N/mm²) Titanium nitride 14.71 Tantalum nitride 15.69 Silicon 15.21Silicon nitride 14.03 Silica 14.94 Silicon carbide 13.37 Tantalum 13.96Titanium 14.07 Polyimide 13.02

EXAMPLE 24 Determination of the Chemical Stability

The polymer 1 was applied from a 20% strength solution (solvent: NMP) toa 4″ silicon wafer by spin coating, at 500 rpm for 5 s and at 2 000 rpmfor 25 s. After a short softbake of 1 min at 120° C. and 2 min at 200°C. on a hotplate, the wafer is heated in a nitrogen atmosphere for 1 hat 400° C. in an oven. After cooling to room temperature, the coatedwafer is heated in NMP to 80° C. for 5 h. Thereafter, the wafer is driedin vacuo for 60 min at 200° C. and the mass difference is determined.

The decrease in mass is 0.8%.

EXAMPLE 25 Determination of the Dielectric Constant of Polymer 1

The dielectric constant was measured using the configuration shown inFIG. 1. For this purpose, the polymer 1 was dissolved in NMP (25%strength solution) and the solution was filtered under pressure througha membrane having 0.2 μM pores. This solution was applied by spincoating to a substrate 1 on which a 600 nm thick titanium layer 2 isalready present. The layer 3 is dried at 120° C. and 200° C., in eachcase for 2 min, on a hotplate and then heated at 430° C. for one hour ina nitrogen atmosphere. Titanium electrodes 4 are then sputtered ontothis layer 3 by using a shadow mask shown in FIG. 2. For this purpose,the shadow mask shown in FIG. 2 includes orifices 5 which correspond tothe position of the titanium electrodes 4. The dielectric constant isdetermined using the impedance spectrometer 6 and is 2.31 in thefrequency range from 100 Hz to 1 MHz.

EXAMPLES 26 To 29 Determination of the Dielectric Constants of Polymers2 to 5

The dielectric constant was determined analogously to example 25 inpolymers 2 to 5. The values found are shown in Table 2.

EXAMPLE 30 Comparative Example for Dielectric Constant

A polymer was prepared analogously to Example 1 of U.S. Pat. No.5,077,378 and the dielectric constant is determined as described inexample 25. The value found is likewise shown in Table 2. TABLE 2Dielectric constant of various polymers Example Polymer Dielectricconstant 25 1 2.31 26 2 2.32 27 3 2.44 28 4 2.31 29 5 2.39 30 U.S. Pat.No. 5,077,378 Ex. 1 3.1

1. A method for producing a dielectric, which comprises: using apoly-o-hydroxyamides of Formula I

where E¹ and E², in each case independently, are substituents selectedfrom the group consisting of hydrogen, a hydroxyl group, a saturatedmonovalent hydrocarbon, and an unsaturated monovalent hydrocarbon; Y¹and Y², in each case independently for each position, are a divalenthydrocarbon; Z¹, in each case independently for each position, is astructural unit having a formula selected from the group consisting ofFormula IIa and IIb

the bond (-*) and the substituent -GR⁵ being disposed in the orthoposition relative to one another,

Z², in each case independently for each position, is a tetravalenthydrocarbon composed of groups linked to one another and selected fromthe group consisting of alkyl and aryl groups; R¹, R², R³, and R⁴, ineach case independently, are substituents selected from the groupconsisting of H, —C₆H₅, —(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, -G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)₃,—(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃, —CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂,—C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is a substituent selected from the groupconsisting of H, —CO(CH₂)_(n)—CH₃, —COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, —C(CH₃)₃, —(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —(CH₂)_(n)—C₆H₅,—COO—(CH₂)_(n)—C₆H₅; G is a heteroatom selected from the groupconsisting of oxygen and sulfur; a is an integer from 0 to 1; b has avalue from 1 to 200; c has a value from 0 to 200; d is an integer from 0to 1; n is an integer from 0 to 5; R⁶ is a divalent substituent selectedfrom the group consisting of:

R⁷ is a substituent selected from the group consisting of an alkyl grouphaving from 1 to 10 carbon atoms and an aryl group having from 5 to 22carbon atoms; and e is an integer from 1 to
 10. 2. The method accordingto claim 1, wherein, in E¹ and E², the saturated monovalent hydrocarboncontains a heteroatom.
 3. The method according to claim 1, wherein, inE¹ and E², the unsaturated monovalent hydrocarbon contains a heteroatom.4. The method according to claim 1, wherein at least one of the Y¹substituents has a heteroatom.
 5. The method according to claim 1,wherein at least one of the Y² substituents has a heteroatom.
 6. Themethod according to claim 1, wherein, in Z^(2,) one of the groups has aheteroatom.
 7. A monomer for the preparation of a poly-o-hydroxyamideusable in dielectrics, comprising a backbone having a formula selectedfrom the group consisting of Formula IVa and IV

where R¹, R², R³, and R⁴, in each case independently, are selected fromthe group of substituents selected from the group consisting of H,—C₆H₅, —(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃, —CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂,-G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)₃, —(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is a substituent selected from the groupconsisting of H, —CO(CH₂)_(n)—CH₃, —COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, —C(CH₃)₃, —(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —(CH₂)_(n)—C₆H₅,—COO—(CH₂)_(n)—C₆H₅; and G is a heteroatom selected from the groupconsisting of oxygen and sulfur.
 8. A process for preparingpoly-o-hydroxyamides, which comprises: reacting the monomer according toclaim 7 with a dicarboxylic acid having a formula selected from thegroup consisting of Formulae Va and Vb

where L is a substituent selected from the group consisting of ahydroxyl group and an activating group; and Y¹ and Y², in each caseindependently for each position, are a divalent hydrocarbon.
 9. Aprocess for preparing poly-o-hydroxyamides, which comprises: reactingthe monomer according to claim 7 with an activated dicarboxylic acidderivative having a formula selected from the group consisting ofFormulae Va and Vb

where L is a substituent selected from the group consisting of ahydroxyl group and an activating group; and Y¹ and Y², in each caseindependently for each position, are a divalent hydrocarbon.
 10. Theprocess according to claim 8, which further comprises carrying out thereacting step with a base.
 11. The process according to claim 9, whichfurther comprises carrying out the reacting step with a base.
 12. Aprocess for preparing polybenzoxazoles having a Formula III

where Z¹ has a formula selected from the group consisting of

E¹ and E², in each case independently, are substituents selected fromthe group consisting of hydrogen, a hydroxyl group, a saturatedmonovalent hydrocarbon, and an unsaturated monovalent hydrocarbon; Y¹and Y², in each case independently for each position, are a divalenthydrocarbon; Z^(2,) in each case independently for each position, is atetravalent hydrocarbon composed of groups linked to one another andselected from the group consisting of alkyl and aryl groups; R¹, R², R³,and R⁴, in each case independently, are substituents selected from thegroup consisting of H, —C₆H₅, —(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH (CH₃)₂, -G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)₃,—(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃, —CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂,—C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is a substituent selected from the groupconsisting of H, —CO(CH₂)_(n)—CH₃, —COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, —C(CH₃)₃, —(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —(CH₂)_(n)—C₆H₅,—COO—(CH₂)_(n)—C₆H₅; G is a heteroatom selected from the groupconsisting of oxygen and sulfur; a is an integer from 0 to 1; b has avalue from 1 to 200; c has a value from 0 to 200; and d is an integerfrom 0 to 1; the method which comprises: heating poly-o-hydroxyamideshaving a Formula I

where E¹ and E², in each case independently, are substituents selectedfrom the group consisting of hydrogen, a hydroxyl group, a saturatedmonovalent hydrocarbon, and an unsaturated monovalent hydrocarbon; Y¹and Y², in each case independently for each position, are a divalenthydrocarbon; Z¹, in each case independently for each position, is astructural unit having a formula selected from the group consisting ofFormula IIa and IIb

in which the bond (-*) and the substituent -GR⁵ are disposed in theortho position relative to one another,

Z^(2,) in each case independently for each position, is a tetravalenthydrocarbon composed of groups linked to one another and selected fromthe group consisting of alkyl and aryl groups; R¹, R², R³, and R⁴, ineach case independently, are substituents selected from the groupconsisting of H, —C₆H₅, —(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, -G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)₃,—(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃, —CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂,—C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is a substituent selected from the groupconsisting of H, —CO (CH₂)_(n)—CH₃, —COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, —C(CH₃)₃, —(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —(CH₂)_(n)—C₆H₅,—COO—(CH₂)_(n)—C₆H₅; G is a heteroatom selected from the groupconsisting of oxygen and sulfur; a is an integer from 0 to 1; b has avalue from 1 to 200; c has a value from 0 to 200; d is an integer from 0to 1; n is an integer from 0 to 5; R⁶ is a divalent substituent selectedfrom the group consisting of:

R⁷ is a substituent selected from the group consisting of an alkyl grouphaving from 1 to 10 carbon atoms and an aryl group having from 5 to 22carbon atoms; and p1 e is an integer from 1 to
 10. 13. A process forproducing an electronic component, which comprises: preparing a solutionof a poly-o-hydroxyamide having a Formula I in a solvent

where E¹ and E², in each case independently, are substituents selectedfrom the group consisting of hydrogen, a hydroxyl group, a saturatedmonovalent hydrocarbon, and an unsaturated monovalent hydrocarbon; Y¹and Y², in each case independently for each position, are a divalenthydrocarbon; Z¹, in each case independently for each position, is astructural unit having a formula selected from the group consisting ofFormula IIa and IIb

in which the bond (-*) and the substituent -GR⁵ are disposed in theortho position relative to one another,

Z², in each case independently for each position, is a tetravalenthydrocarbon composed of groups linked to one another and selected fromthe group consisting of alkyl and aryl groups; R¹, R², R³, and R⁴, ineach case independently, are substituents selected from the groupconsisting of H, —C₆H₅, —(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, -G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)₃,—(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃, —CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂,—C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is a substituent selected from the groupconsisting of H, —CO(CH₂)_(n)—CH₃, —COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, —C(CH₃)₃, —(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —(CH₂)_(n)—C₆H₅,—COO—(CH₂)_(n)—C₆H₅; G is a heteroatom selected from the groupconsisting of oxygen and sulfur; a is an integer from 0 to 1; b has avalue from 1 to 200; c has a value from 0 to 200; d is an integer from 0to 1; n is an integer from 0 to 5; R⁶ is a divalent substituent selectedfrom the group consisting of:

R⁷ is a substituent selected from the group consisting of an alkyl grouphaving from 1 to 10 carbon atoms and an aryl group having from 5 to 22carbon atoms; and e is an integer from 1 to 10; applying the solution toa substrate; evaporating the solvent to obtain a film; heating the filmto cyclize the poly-o-hydroxyamide having the Formula I to yield apolybenzoxazole having a Formula III

where Z¹ has a formula selected from the group consisting of

E¹ and E², in each case independently, are substituents selected fromthe group consisting of hydrogen, a hydroxyl group, a saturatedmonovalent hydrocarbon, and an unsaturated monovalent hydrocarbon; Y¹and Y², in each case independently for each position, are a divalenthydrocarbon; Z², in each case independently for each position, is atetravalent hydrocarbon composed of groups linked to one another andselected from the group consisting of alkyl and aryl groups; R¹, R², R³,and R⁴, in each case independently, are substituents selected from thegroup consisting of H, —C₆H₅, —(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, -G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)₃,—(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃, —CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂,—C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is a substituent selected from the groupconsisting of H, —CO (CH₂)_(n)—CH₃, —COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₂, —C(CH₃)₃, —(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —(CH₂)_(n)—C₆H₅,—COO—(CH₂)_(n)—C₆H₅; G is a heteroatom selected from the groupconsisting of oxygen and sulfur; a is an integer from 0 to 1; b has avalue from 1 to 200; c has a value from 0 to 200; and d is an integerfrom 0 to 1; structuring the film to obtain a resist structure havingtrenches; depositing a conductive material on the resist structure sothat the trenches are filled with a conductive material; and removingexcess of the conductive material.
 14. A process for producing anelectronic component, which comprises: preparing a solution of apoly-o-hydroxyamide in a solvent, the poly-o-hyroxyamide having aFormula I

where E¹ and E², in each case independently, are substituents selectedfrom the group consisting of hydrogen, a hydroxyl group, a saturatedmonovalent hydrocarbon, and an unsaturated monovalent hydrocarbon; Y¹and Y², in each case independently for each position, are a divalenthydrocarbon; Z¹, in each case independently for each position, is astructural unit having a formula selected from the group consisting ofFormula IIa and IIb

in which the bond (-*) and the substituent -GR⁵ are disposed in theortho position relative to one another,

Z², in each case independently for each position, is a tetravalenthydrocarbon composed of groups linked to one another and selected fromthe group consisting of alkyl and aryl groups; R¹, R², R³, and R⁴, ineach case independently, are substituents selected from the groupconsisting of H, —C₆H₅, —(CH₂)_(n)—CH₃, -G-(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH (CH₃)₂, -G-CH(CH₃)₂, —C(CH₃)₃, -G-C(CH₃)₃,—(CF₂)_(n)—CF₃, -G-(CF₂)_(n)—CF₃, —CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂,—C(CF₃)₃, —N(CH₃)₂, —N(CF₃)₂,

R⁵, in each case independently, is a substituent selected from the groupconsisting of H, —CO(CH₂)_(n)—CH₃, —COO—(CH₂)_(n)—CH₃, —(CH₂)_(n)—CH₃,—CH((CH₂)_(n)CH₃)₂, —CH(CH₃)₃)₂, —C(CH₃)₃, —(CF₂)_(n)—CF₃,—CF((CF₂)_(n)CF₃)₂, —CF(CF₃)₂, —C(CF₃)₃, —(CH₂)_(n)—C₆H₅,—COO—(CH₂)_(n)—C₆H₅; G is a heteroatom selected from the groupconsisting of oxygen and sulfur; a is an integer from 0 to 1; b has avalue from 1 to 200; c has a value from 0 to 200; d is an integer from 0to 1; n is an integer from 0 to 5; R⁶ is a divalent substituent selectedfrom the group consisting of:

R⁷ is a substituent selected from the group consisting of an alkyl grouphaving from 1 to 10 carbon atoms and an aryl group having from 5 to 22carbon atoms; and e is an integer from 1 to 10; applying the solution toa substrate having a surface with metallic structures and trenchesformed between the metallic structures; evaporating the solvent to fillthe trenches with the poly-o-hydroxyamide of the Formula I; and heatingthe substrate to cyclize the poly-o-hydroxyamide of the formula I toyield the polybenzoxazole having a Formula III.